We show that a dilute ensemble of epoxy-bonded adatoms on graphene has a tendency to form a spatially correlated state accompanied by a gap in graphene’s electron spectrum. This effect emerges from the electron-mediated interaction between adatoms with a peculiar $1/r^3$ distance dependence. The partial ordering transition is described by a random bond three-state Potts model.

• Received 16 September 2009

DOI:https://doi.org/10.1103/PhysRevB.80.233409